A mutant of Balb 3T3 cells was isolated that has the morphologic phenotype of transformed cells but is not transformed. Its transformed appearance is due to its low adhesion which in turn is due to a defect in glycoprotein synthesis. A 78,000 dalton membrane has been isolated from RSV-transformed CEF and found to be present in glucose-starved normal cells. BIBLIOGRAPHIC REFERENCES: Pouyssegur, J. and Pastan, I.: Mutants of mouse fibroblasts altered in the synthesis of cell surface glycoproteins preliminary evidence for a defect in the acetylation of glucosamine-6-phosphate. J. Biol. Chem., 252: 1639-1646, 1977. Willingham, M.C., Yamada, K.M., Yamada, S.S., Pouyssegur, J., and Pastan, I.: Microfilament bundles and cell shape are related to adhesiveness to substratum and are dissociable from growth control in cultured fibroblasts. Cell, 10: 375-380, 1977.